Shape adaptive IRS based SAG IoT network

Abstract6G technology connects physical and digital, and ubiquitous 6G services will provide convenience to users around the world. The concept of the world-earth integrated network is to seamlessly integrate these three subnets to better adapt to future development. This article introduces the world-earth integrated network and shape-adaptive IRS antenna technology. The shape-adaptive IRS antenna described in this article is made of flexible materials, and the physical shape of the antenna can be changed according to different situations, and specific radiation beams can be generated according to functional requirements. And the effectiveness of the shape-adaptive IRS antenna technology has been proven in the simulation results.

Reducing fetal radiation dose in computed tomography for pregnant patients: A literature review

To diagnose diseases during gestation period including renal stones, appendicitis, and pulmonary embolism in pregnant patients, computed tomography (CT) can be a golden standard. Due to CT examination, the fetus is prone to receiving a considerable dose which is the result of direct or scattered (external and internal scattered radiation) beams. The effects of ionization radiation on fetus include mutagenesis and carcinogenesis, therefore, it is essential to reduce fetus dose for pregnant patients who undergo CT examination during gestation period. This article aims to review approaches that are effective in reducing fetal dose in pregnant patients.

Pharmacological Interventions for the Prevention and Treatment of Kidney Injury Induced by Radiotherapy: Molecular Mechanisms and Clinical Perspectives

: More than half of cancer patients need radiotherapy during the course of their treatment. Despite the beneficial aspects, the destructive effects of radiation beams on normal tissues lead to oxidative stress, inflammation, and cell injury. Kidneys are affected during radiotherapy of abdominal malignancies. Radiation nephropathy eventually leads to the release of factors triggering systemic inflammation. Currently, there is no proven prophylactic or therapeutic intervention for the management of radiation-induced nephropathy. This article reviews the biomarkers involved in the pathophysiology of radiation-induced nephropathy and its underlying molecular mechanisms. The efficacy of compounds with potential radio-protective properties on amelioration of inflammation and oxidative stress is also discussed. By outlining the approaches for preventing and treating this critical side effect, we evaluate the potential treatment of radiation-induced nephropathy. Available preclinical and clinical studies on these compounds are also scrutinized.

Shape adaptive IRS Enhanced SAG IoT Network

6G technology connects physical and digital, and ubiquitous 6G services will provide convenience to users around the world. The concept of the world-earth integrated network is to seamlessly integrate these three subnets to better adapt to future development. This article introduces the world-earth integrated network and shapeadaptive IRS antenna technology. The shape-adaptive IRS antenna described in this article is made of flexible materials, and the physical shape of the antenna can be changed according to different situations, and specific radiation beams can be generated according to functional requirements. And the effectiveness of the shape-adaptive IRS antenna technology has been proven in the simulation results.

Full-duplex reflective beamsteering metasurface featuring magnetless nonreciprocal amplification

Nonreciprocal radiation refers to electromagnetic wave radiation in which a structure provides different responses under the change of the direction of the incident field. Modern wireless telecommunication systems demand versatile apparatuses which are capable of full-duplex nonreciprocal wave processing and amplification, especially in the reflective state. To realize such a functionality, we propose an architecture in which a chain of series cascaded radiating patches are integrated with nonreciprocal phase shifters, providing an original and efficient apparatus for full-duplex reflective beamsteering. Such an ultrathin reflective metasurface can provide directive and diverse radiation beams, large wave amplification, steerable beams by simply changing the bias of the gradient active nonmagnetic nonreciprocal phase shifters, and is immune to undesired time harmonics. Having accomplished all these functionalities in the reflective state, the metasurface represents a conspicuous apparatus for efficient, controllable and programmable wave engineering.

Holographic Transmitarray Antenna with linear Polarization in X band

In this paper, we present the design and demonstration of transmitarray antennas (TAs) based on the holographic technique for the first time. According to the holographic theory, the amplitudes and phases of electromagnetic waves can be recorded on a surface, and then they can be reconstructed independently. This concept is used to design single-beam and multi-beam linearly polarized holographic TAs without using any iterative optimization algorithms. Initially, a transmission impedance surface is analyzed and compared with the reflection one. Then, interferograms associated with the scalar admittance distribution are defined according to the number and direction of the radiation beams. After that, a transmission metasurface of dimensions equal to 0.26λ0 is hired to design holographic TAs at 12 GHz. Several examples are provided to support the method. In the end, a linearly polarized circular aperture wideband holographic transmitarray antenna with a radius of 13.3 cm has been manufactured and tested. The antenna achieves 12.5% (11.4-12.9 GHz) 1-dB gain bandwidth and 23.8 dB maximum gain, leading to 21.46% aperture efficiency.

Full-duplex Reflective Beamsteering Metasurface Featuring Magnetless Nonreciprocal Amplification

Nonreciprocal radiation refers to electromagnetic wave radiation in which a structure provides different response under the change of the direction of the incident field. Modern wireless telecommunication systems demand versatile apparatuses which are capable of full-duplex nonreciprocal wave processing and amplification, especially in the reflective state. Here, we propose full-duplex reflective beamsteering metasurfaces for magnetless nonreciprocal wave amplification. To realize such a unique, extraordinary and versatile functionality, we propose a completely new architecture in which a chain of series cascaded radiating patches are integrated with nonreciprocal phase shifters, providing an efficient mechanism for wave reception, signal amplification, nonmagnetic nonreciprocal phase shifting and steerable wave reflection. Having accomplished all these functionalities in the reflective state, the metasurface represents a conspicuous apparatus for efficient, controllable and programmable wave engineering for wireless telecommunications. Such an ultrathin reflective metasurface can provide directive and diverse radiation beams, and steerable beams by simply changing the bias of the gradient active nonmagnetic nonreciprocal phase shifters. The proposed structure provides large wave amplification and is immune to undesired time harmonics, yielding a highly efficient full-duplex reflective beamsteering apparatus.

Dual-band beam steering THz antenna using active frequency selective surface based on graphene

A dual-band independently beam steering THz antenna is presented, which is composed of a broadband omnidirectional monopole source antenna surrounded by six hexagonal active frequency selective surface (AFSS) screens with switchable filtering response in two bands. By controlling the chemical potential from 0 eV to 0.5 eV, the AFSS screen can achieve the conversion between high transmission (ON state) and almost total reflection (OFF state) at two frequency ranges independently. Therefore, the radiation beams of the THz antenna in two bands can be steered from 360° large angle scanning and omnidirectional radiation with flexible combinations.